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D. M. CLARK,

ADJUSTABLE ELECTRODE SPARK PLUG.

APPLICAHON FILED MAY 7, 1915. RENEWED Nov. 10.1917.

Patented Feb; 12; 1918.

, "I. swmmtoz MQMM CLARK, F JAZZESBURG, NEYV JERSEY.

ABDFUSTAELE-ELEBTRGDE SPARK-EL'UG.

DANIEL M. CLARK, a Led States, residing a; onnty of ldiddlesezr and to adjustable elecwidth of the d. and has for its obspark plug Mi. the stationary electrode 'c cleared of any carbon deddirion, sparlrplngs constructed a with this invention are fun i handle provided with an insoar and attached to she movelectrode so that when the re turn the electrode the ondingly inoved. A snitadiacenily or upon the poin'sed to or swept s, the distance moved cirodewith relation i0 corrode, which. distance is 7 he pointed out upon the is is also an object provide number of movable and a, in construe; means 1e movable electrodes and ap upon a scale supf is also an object; scans for redie movable elecbe accomplished by fixing osiiion through the agency einal ier specified, so that e electrodes heinc once ents of the i lustrated the char "cart" 2-; glen Specification of Letters Eatent.

Patented Feb. 1%, 19918.

flied .iey '2, 1915, Serial. l lo. 26,622. Renewed November 10, 1817. Serial No. 201,408.

is a cross-section on the horizontal broken line w-w of Fig. 1. Fig. 4 is a side View, partly in vertical. section, showing the means for operating the movable electrodes of more than one sparkplug, with the devices for indicating the spark gap and for securing the members in position after they have been adjusted.

In the drawings, and throughout the description the same letter is used to refer to the same part.

Considering the drawings, the sparkplug has the meiallic body portion A, and a central stationary insulated electrode a. There is provided a revoluble electrode B having as its lower end conical gas check C, and

the electrode is rotatively movable in a pas.-

sage extending lengthwise through the wall of the body A. The lower end or the inevable electrode is marked D and it is bent as shown and constructed to be turned into a wiping contact with the end of the stationary elect-rode, as best shown in Fig. 3.

The passage 0 as shown extends lengthwise through the wall of the body A, which is the external metallic body. In all the sparlrplugs or" this character with which this applicant is acquainted, the adjustable electrode passes through the porcelain, and, the porcelain forms the central member of the plug. It is necessary to hook or otherwise lic contact with the bod and, therefore, with,

the engine or ground, as shat term is em ployed, the outer end of the movable elec trode is most conveniently placed formjush ing the electrodes of several plugs together by a connection {Tom the dash as described herein. X y

An insulating handle E is secured a) she niovahle electrode b means ofa nut 59, and the handle is proviced with an indicator or e arranged ahove'and intended "so move over the scale F that is secured externally upon the body portion. The handle 15 substantially horizontal and the scale is p6 sitioned accordingly. As shown, the pas sage e in the wall of the body portion, and, consequently, the attitude of the electrode B is necessarily slightly inclined.

in Fig. 4c, thi invention is illustrated as comprising more than one sparkplug. The sparkplugs G and g are connected by the posts H and IL with a rack bar J having the toothed portion or rack j. The connections are or like construction for each sparkplug. Thus, the post it has a clamp it that engages the rounded end of the handle E. The handle E is in all respects similar in structure to the handle E, best shown in Fig. 2, and it is: provided with an indicator such as the indicator 0, but not shown. The scale F is alike in its form and arrangement with the scale F. The movable electrode B of the sparkplug G is secured to the handle E by means of the nut b. \Vhatever the number of sparkplugs employed, they may each have the handle with the indicator and the scale, or the indicator and scale may be omitted upon each sparkplng when there are a number of sparkplugs, and the scale member and indicator may be otherwise disposed as explained below.

The rack bar H is caused to move back and forth by the engagement of the rack and the toothed sector K on the transverse short shaft is, which is mounted in the bearings L supported by the dashboard Z. A handle M, passing through and operating in a slot m in theboard, has one of its ends connected with the shaft 70, and the other end is provided with a handpiece N that is threaded internally and engages the like threaded end a of the handle. The handle sweeps a scale P borne by the board, and an indicating arrowhead Q, or the like may be placed upon the handle to point to the scale.

In the operation of this invention, assuming each sparkplug to be constructed as shown in Fig. 1, Fig. and Fig. 3, it is believed to be made out by the foregoing description that when the movable electrode is turned by the handle 1), its bent end D will rub against the end of the stationary electrode a, and this may be done a sullicient number of times to fully clear the electrodes of carbon deposit. It is also believed to be apparent that the movement of the electrode corresponds to the movement of the indicator 6 over the scale F, and the dis tance of one (Electrode lromd'he" other may be determined by considering the position of the in licalor with respect to the scale F.

When there are more than one sparkplug, and the devices shown in Fig. l are employed, the spark gap is indicated upon the scale I and, the handle M being placed as desired to suitably separate the electrodes of I having athe plugs, its position may be fixed by turning the screw-threaded handpieceinto contact with the scale P. Where a number of plugs are used andthe movable electrodes thereof are operated together, it is necessary for the operator to know the extent of the sparkgaps with certainty, and he must be able to secure the parts firmly after adj ustment. The position of the handle M upon scale P plainly indicates the size of the' sparkgaps, and by screwing up the handpiece N firmly, the sparkgaps cannot be varied by the vibrations of the engine or movements of the vehicle. A number of changes in the precise construction and arrangement of the parts illustrated would naturally suggest themselvesto a mechanician familiar with electrical ignition systems and devices, and it is not intended to narrowly confine this invention to the forms and members as set forth.

Having now described this invention, and explained the mode of its operation, what I claim is 1. In adjustable electrode sparkplugs, the combination with a series of sparkplugs each having a freely movable electrode by the movement of which the sparking distance between the ends of the electrodes may be varied, of means connected with the said movable electrodes of all the sparkplugs for moving said electrodes thereby adjusting the spark gaps between the ends of the electrodes from a distance, a scale arranged at a distance from the said sparkplugs, a member connected with the said electrodes'adjusting means and arranged to sweep the said scale, and releasable means for securing the member at any point upon the scale thereby holding the said electrodesadjusting means in a desired position.

2. In adjustable electrode spai-kplugs, the combination with a series of sparkplugs each having a freely movable electrode by the movement of which the sparking distance between the electrodes may be varied, means connected with the said movable electrodes of all the sparkplugs for moving the said electrodes thereby adjusting the spark gaps between the ends of the electrodes from a distance, devices arranged at a distance from the sparkplugs for indicating the extent of movement of the said electrodes-adjusting means, and securing means arranged adjacent to the said indicating devices for rcleasably securing the said devices and electrodes-adjusting means in a desired posi' tion.

3. In adjustable electrode sparkplugs, the combination with a hollow metallic body portion, of an insulated stationary electrode arranged centrally within the said body, a movable electrode having a conical was cheek near its lower end, the said metallic body passage extending lengthwise through its wall and having its lower porward or from the lower end of the stationtion formed to fit the said conical gas check, ary electrode, and means located exteriorly the said movable electrode occupying the and connected with the top of the movable 10 said passage and being arranged to turn on electrode for turning the electrode and for 5 its own axis therein, the said electrode havsecuring the same in any position.

ing a lower end below the said gas check In testimony whereof Jfaflix my signature. constructed to be moved horizontally to- I DANIEL M. CLARK. 

